Start-stop regenerative repeater



Jam-4,1938. L. M. POTTS 3 START-STOP REGENERATIVE REPEATER I Filed Feb.16, 1934 INVENTOR LOU/5 M.

' POTTJ ATTO EY Patented Jan. 4, 1938 SPATENT .QFFICE START-STOPREGENERAT'IVE REPEATER Louis M. Fctts, Evanston, 111., assignor to Tele-Qorporation, Chicago, 111., a corporation or" Bela-Ware February 16,1934, Serial No. 711,479

30 Claims;

This invention pertains to telegraphy and more particularly to theautomatic transmission of telegraphic signal codes from one line sectionto another.

In telegraph systems using comparatively long signal impulses, relayrepeaters which renew the current value in each impulse but which maymodify the length of the impulses slightly have been found satisfactoryfor some telegraphic purposes, but in systems where transmission, iseffected at high speeds, it becomes necessary to preserve the relativelengths of signal impulses well as to renew the current strengththereof. Accordingly, an object of this invention is to provide arepeater for start-stop systems of automatic telegraphy in whichreceived signal impulses are reproduced and retransmitted in renewedstrength and in faithful reproduction of their relative time value,thereby producing a complete regeneration of the signal impulses andsignal conditions as originally created and transmitted.

Further features are to repeat and regenerate the start and stop controlimpulses as, well as the intelligence impulses and to provide astartstop regenerative repeater in which relative lengths ofretransmitted impulses are determined locally by mechanical means, butin which an electrical characteristic of each repeated impulse isdetermined by a received signal impulse to which the retransmittedimpulse corresponds.

These and other objects are attained by utilizing the principles of aspeed regulated motor shaft and start-stop control for synchronizing thereceiving and retransmitting functions taken in connection with camcontrolled retransmitting contacts which, by start-stop principles, arekept in synchronism with the incoming signal impulses.

The system of this invention comprises a regenerative repeater which isassociated with a circuit arrangement to repeat in but one direction,but it is to be understood that the apparatus is such that it may beused in circuit systems in which repeating in both directions upon asingle telegraphic line system may be conducted. Apparatus achievingsuch an object is disclosed in copending application Serial No. 755,253,filed Nov. 30, 1934. a

A The apparatus of the present invention comprises astart-stop cam orset of cams with a driving motor and with a clutch which permits thecams to be normally stopped but in condition to be started in responseto a received signal.

In response to a received starting impulse, the

cams start and continue in motion for a complete code cycle ofoperation, then come to rest in readiness for the next cycle.Retransmitting contact points are arranged to be dually controlled,first by the cams to determine the length of every signal impulse andsecond, by means responsive to received signal impulses to determine theelectrical characteristic of each retrans mitted impulse according tothe received impulse which it represents, the start impulse and stopimpulse being repeated as well as the intelligence impulses of each codegroup of impulses.

A better understanding of the invention may be had from the followingdescription, taken in connection with the accompanying drawing, 15wherein :Fig. 1 shows a telegraphic system comprising two line circuitsassociated in signal repeating relation by a repeater of preferred typeaccording to the present invention;

Fig. 2 shows an alternative type of repeater;

Fig. 3 shows a detail of the repeater of Fig. 2;

' Fig. 4 shows a modification of the repeater of Figs. 2 and 3;

Fig. 5 shows an alternative type of repeater;

Fig. 6 shows a detail of the repeater of 5;

Fig. 7 shows a modification of the repeater of Fig. 5; and- Fig. 8 showsa starting latch.

Referring to Fig. 1, a controlling line circuit includes battery I,receiving magnet 2', line wire 3, remote transmitter 4, and ground 5,and a controlled line circuit includes battery ti, resistor 'I, contact8, contact 9, line wire H3, receiver magnet II; and ground I2. Magnet 2has an armature i5 pivoted at I6 with retractile spring I'I havingselective abutments I8, I9, and with a striker 20 for controlling astarting mechanism, not shown, for starting a cam sleeve 2!. Thestarting mechanism may be of the type shown in Patent No. 1,783,382,issued to H. L. Krum and comprising in part a friction clutch and aclutch releasing latch, although any other type of clutch and latchsuitable for printing telegraph equipment may be used. In Fig. 8, uponrelease of .45 armature I5, striker 2|] pushes pin H5, which rotateslevers IIS and II! to release a starting latch IIB whose tooth II9releases arm ill! fixed upon friction-urged cam sleeve 2|. Cam sleeve 2iis associated through a friction clutch with a constantly operatingpower shaft 26, and carries a multiple cam 21 having lobes whichconsecutively engage a cam follower 28 pivoted at 29 with retractilespring 30. Follower 28 has also a-socket arm 33 which surrounds a disclike head 34 of T-member 35 which has abutment extensions 36, 3? and aslotted arm 38. Within the slotted arm 38 is contained an operating pin42' fixed upon lever 43, pivoted at 44, and having jockey 45. Striker 46secured to member 35 engages contact 41 to move it into engagement withcontact 9 normally in engagement with contact 8.

In operation, the structure shown in Fig. 1 normally has magnet 2energized, its controlling circuit being normally closed at transmitter4 as shown, with its armature in operated position as shown. Signalimpulses are transmitted over line 3 in code groups of seven impulsesper group, each group beginning with a spacing or open impulse andterminating with a marking or current impulse. The first signal,spacing, of a re ceived code of signals will deenergize magnet 2 andrelease armature l5, thus causing striker 20 to start cam sleeve 2! andalso will position abutment l9 in apposition with abutment 36.Immediately cam 21 starts revolving and lobe 50 operates follower 28 tooperate T-member 35, which causes abutment 36 to engage abutment IS andwhich rotates member 35 upon abutment l9 as a fulcrum, so that slottedarm 38 acts through pin 42 to rotate lever 43 which is locked in itsoperated position by jockey 45 and which, in its operated position,operates contact 4'! to engage contact 9 and to lift contact 9 away fromcontact 8, thus opening controlled line circuit I0 and repeating aspacing signal of nocurrent in controlled line circuit In in response toa similar spacing signal in controlling line circuit 3.

The above described action comprises repeating the starting signalimpulse of a code, following which. five intelligence impulses and astop impulse are repeated by cam lobes 5| to 56 inclusive in cooperationwith armature I5 controlled by magnet 2. As each lobe 50 to 55 inclusiveopcrates follower 28, the member 35 is moved to engage either abutmentIE or abutment l8 and therefore operates lever 43 to or from its markingposition as shown accordingly as a received signal impulse is-marking orspacing in nature. A signal in controlling line circuit 3, whethermarking or spacing, determines the condition of magnet 2, whetherenergized 'or deenergized, which determines the position of armature l5,whether attracted for marking or released for spacing, which determinesthe efiectively positioned one of abutments l8, [9, whether [8 formarking or H] for spacing, after which the retransmitted impulse will bedetermined in feature of its duration and in feature of its elapsed timerelation to the starting impulse wholly by the mechanical action of thecam 2'! which is driven by a local motor running at a constant speed,and the retransmitted impulses thus are given relative lengthsdetermined by local mechanical means at the repeating apparatusregardless of the relative length of the marking and spacing signals asreceived by magnet 2 over line circuit 3.

In an apparatus for polar working, magnet 2 may be of polar type andcontact 41 may be con-' nected through a resistor as 1 to a battery as6, but of reversed polarity, the contact 9 then cooperating withcontacts 8 and 41 to produce polar reversals of current in line IE asthe contacts are operated by lever 43.

An alternative mechanical form of the invention is shown in Figs. 2 and3. For a more comprehensive explanation of the mechanical details ofthis structure, reference may be had to Patent No. 1,821,110 issued toS. Morton et al. September l, l931,'and to Figs. 1 and 3 thereofparticularly. Cam barrel 5| symbolizes a complete printer such asdisclosed in the patent to Morton et al. and when taken with theaddition of signal lever 52 and multiple lobe earns 53 and 54' formarking and spacing signals respectively, Fig. 3 discloses a combinationprinter and start-stop regenerative repeater. Cam barrel 5| has stop arm55' which engages a fixed stop dog 56 and a signal lever 52',corresponding to signal lever 43' in Fig. l','has jockey 51corresponding to jockey 45 in Fig. 1, and has striker 58 correspondingto striker 46 in Fig. 1 whereby contacts 41', 9', and 8' are operated asin Fig. 1.

In the Morton et al. printer, the cam barrel 5! has sixlp-airs oi cams50' which control six selector levers in accordance with six receivedintelligence impulses, operating the selector levers sequentially toregister each impulse as the intelligence impulses are received, afterwhich a transfer action occurs which transfers the six registrationssimultaneously to the selectorand printing mechanism'of the printer.Added to the Morton et al. mechanism is the special signal lever 52' forrepeating the received impulses. The special lever 52? is coaxial withthe six regular selector levers of the printer, and operates to markingand to spacing positions in a manner similar to the operation of theprinter se- 7 lector levers but operates for every impulse of the entiresignal including start and stop impulses. With every movement of thespecial signal lever 52 it changes the contactual relations of thecontacts 8, 9', and 41' and causes them to transmit to the controlledline section I0 a signal impulse corresponding to the instant signalimpulse in the controlling line section. The special signal lever 52' isnot associated with the transfer mechanism which cooperates with the sixsignal levers of the printers printing mechanism, so that the transferaction and subsequent actions of the printer are not effective upon theretransmission mechanism.

V In operatic-n, as a repeater, the structure shown in Figs; 2 and 3normally has cam barrel 5! in position toward the left as shown, itbeing held in that position under control of an energized line magnetcorresponding to magnet 2 in line circuit 3 of Fig. 1. Signal impulsesare transmitted over line 3 in code groups of seven impulses per group,each group beginning with a spacing or open impulse and terminating witha marking or current impulse. The first signal, spacing, of a receivedcode of signals will release cam barrel 5i, as will be understood fromthe Morton'et al. patent. The cam barrel will move toward the right toclear stop dog. 56, will move marking cam 53 away from upper camfollower 59 of lever 52', move spacing cam 54' into position'toengagelower cam follower 60 of lever 52,

and will begin a revolution at regulated speed. Immediately thereafter,a lobe of cam 54' engages follower BD and moves lever 52' into itsalternative position and operates striker 58 and contacts 41' and 9,thereby disengaging contact 6 from contact 8 and opening controlled linecircuit l0 and repeating a spacing signal impulse of no-current incontrolled line circuit ID in response to a similar spacing signalimpulse in controlling line circuit 3. The above described actioncomprises repeating a starting signal impulse of a code, following whichfive intelligence impulses and a stop impulse are repeated by cam barrel5! in cooperation with contacts 41, 9,

and 8'. As each impulse, whether marking or spacing, operates cam barrel5! to left or to right accordingly as the controlling impulse is markingor spacing, lever 52 is brought under control of cam 53 or 54accordingly as the impulse is marking or spacing, and a lobe of the theneffective cam 53 or 54 determines the position of lever 52, which inturn determines the operation of contacts 41', 9', and 8. The timeduration and electrical nature of a retransmitted impulse, and its timerelation to its starting impulse, will be determined wholly by themechanical action of cam barrel 5! which is driven by a local motorrunning at a constant speed, while the electrical nature of eachretransmitted impulse will be determined by the left or right positionof cam barrel 5i as determined in turn by the marking or spacing natureof a signaling impulse of the instant electrical signal in thecontrolling line.

In Fig. 4 is shown a development of cams 53 and 54 shown in normal formin Figs. 2 and 3. A modification is shown in cam lobes 53A and 54A inthat the two said lobes are extended in axial dimension in such mannerthat lobe 54A always engages cam follower 60 to operate signal lever 52whether cam barrel 5!! is positioned to right or to left by a receivedsignal, and lobe 53A always engages cam follower 59 to operate signallever 52 whether cam barrel 50 is positioned to right or to left. Thus,start and stop signals of proper timing and of proper electricalcharacteristic are sent to line H) independently of control by anyreceived signal, and only the intelligence impulses are repeated underdirect control of received signals.

A further mechanical type of the invention is shown in Fig. 5 with adetail in Fig. 6. For a more comprehensive explanation of thisstructure, reference may be had to Patent No. 1,370, 669, issued to L.M. Potts, March 8, 1921, and to Fig. 18 thereof particularly. In thePotts patent is disclosed a method of operating a receiving device inwhich a detector lever is supported loosely at both ends and is springtensioned near one end and between the supports. A can: applies power toa median point of the lever and the non-tensioned end ope-rates if thelever is unrestrained, but should the non-tensioned end be restrained asa result of a line signal, then the tensioned end of the lever willrespond to the cam. Thus a spacing signal impulse of no-current in theline circuit will restrain the nontensioned end of the detector leverand cause the cam to operate the tensioned end of the detector lever tooperate in turn a signal lever to register a space signal, while amarking signal impulse of current in the line circuit will not restrainthe detector lever and will permit the cam to operate the non-tensionedend of the detector lever to operate in turn a signal lever to registeror indicate a marking signal impulse.

In the structure of Figs. 5 and 6, illustrated in two sectional views inexploded arrangement of upper and lower views a continuously operatingmotor power shaft BI is connected through a friction clutch with asingle cam sleeve 62 which sleeve is integral with one cam 63 in theupper view and with five pairs of mated cams as and 65 in the lowerview, the eleven cams cooperating spring 59 against stop l0 and pivotalstop H with cam follower l2 projecting into the path of lobes l3 and Mof cam 63. Striker 17 on cam follower lever 68 may engage lug 18 onsignal lever 15] pivoted at 8% to rotate lever 'Hl clockwise, andstriker 8! on cam follower lever 68 may engage lug 82 on signal lever 19to rotate lever 19 counterclockwise. Signal lever 19 is normallyrestrained by jockey 83 and operates contacts 84. Magnet 85 shown in thelower view has an armature E36 which is pivoted at B? and which hasretractile spring 88 and which has also an operating edge 90 shown inboth upper and lower views which normally is out of the path of ends illof lever 63 in the upper view and Q 5 in the lower view, and normally isheld in that position by energization of magnet 85 corresponding tomagnet 2 of Fig. l. Armature 35 has also a cam-starting striker 92corresponding to striker Zll in Fi 1.

Cam 64 cooperates with a cam follower lever 95 which is held yieldinglyby spring 96 against stop H3 and pivotal stop 1! with cam follower 91projecting into the path of cam 64. Striker as on cam follower lever 95may engage lug 99 on signal lever [02, pivoted at 88, to rotate lever 32clockwise.

Gain 65 cooperates with a cam follower lever lot which is heldyieldingly by a spring similar to 9 3 against stops 1B and ii with a camfollower similar to an projecting into the path of cam 55.

Striker led on cam follower lever I63 may engage lug 595 on signal leverN52 to rotate lever H12 counterclockwise. Lever I03 is largely obscuredby lever 95 in Fig. 5. The contour of lever IDS is similar to thecontour of lever 95 except that lever H33 terminates at I06 and hasneither operating end 9! nor striker 98 for rotating lever seaclockwise, but has instead striker lil l for rotating lever lllZcounterclockwise. Both levers 95 and it? are guided by comb Hl'l, Fig.5, in which lever 95 moves freely in a deep notch and in which lever M13is restrained by a shallow notch against movement in response tocam 65,Fig. 5.

Signal lever 12 operates contacts Hi8, there being five pairs of cams64, 65, five pairs of cam follower levers 95, N33, five signal leversH32, and

five pairs of contacts H28 all corresponding to five intelligence signalimpulses in a received code of impulses, additional similar equipmentbeing provided when longer codes are served. Successive pairs of cams$4, $5 are spaced at successive angles upon cam sleeve 62. A controlledline circuit extends from ground Hi through battery H2 and resistor H3,then through all contacts I08 and 84 in parallel to line wire H4.

In operation generally, in the structure of Fig. 5, cam lobe 73 operateslever 19 to open contacts 84 to repeat a starting signal of spacing oropen electrical nature, followed by successive operation of five leversM2 to operate five pairs of In operation specifically, when a startingsignal impulse of open circuit condition deenergizes magnet 85, armature86 is operated by spring 88 and striker 92 operates a clutch (not shown)to start cam sleeve 62 and its earns 63, i5 5, and 65. Armature 86 beingdeenergized, operating edge 90 now is positioned in the path of all ends9| and cam lobe 13 engages follower l2 and operates lever 68 which beingrestrained at end 9| by edge 90 rotates upon edge 90 as a fulcrum andcauses spring 69 to yield, thus causing striker 8| to operate lever 19which rotates upon its pivot and operates contacts 84 to openretransmission circuit IE4. This constitutes the repeating of thestarting impulse of a code now being received. At a time instantthereafter, during a median part of the first intelligence impulsesignal, signal receiving magnet 85 will be energized or deenergizedaccording to the marking or spacing nature of the first intelligencesignalimpulse, armature 86 will be attracted or unattracted according tothe marking or spacing nature of the impulse, edge 90 will be out of orin the path of end 9| of the first lever according to the marking orspacing nature of the impulse, first cam 64 will engage first camfollower 91 and willoperate end 9! on H as a fulcrum or will operate endI20 on Silas a fulcrum according to the marking or spacing nature of theimpulse, as a,

result of which the first lever I02 will be moved clockwise byengagement of striker 98 with lug 99 or will not be moved according tothe marking or spacing nature of the impulse, by which the first pair ofcontacts I98 will be closed or will remain open according to the markingor spacing nature of the first intelligence signal impulse, thusrepeating in the controlled circuit I I6 the instant marking or spacingsignal impulse of a controlling circuit in which magnet 85 is included.Thereafter at a similar instant of the second intelligence signalimpulse, cam 65 invariably will engage cam follower (not shown) of leverI83 and invariably will operate striker we to operate lever I02counterclockwise to permit the first contacts IRS to open, thisrestoration of the first pair of contacts occurring simultaneously withthe operation of the second lever 102 by the cam 64 of the second pairof cams, thus terminating the first retransmit-ted intelligence impulseand initiating the retransmission of the second 7 intelligence signalimpulse. In like manner the third, fourth, and fifth intelligence Isignal impulses are repeated, and as the fifth cam 55 terminates thefifth retransmitted intelligence signal impulse, cam lobe 14 operateslever 68 for retransmission of the stop signal impulse which always isof marking nature with magnet 85 energized, with armature 8 5 attracted,and with edge 90 out of the path of end 9| of lever 68 and striker Tlinvariably is operated to engage lug 73 to rotate lever 79 to causecontacts 84 to close, thus retransmitting the stop signal. In thetransmission of the code as described, each instant of beginning andending ofevery retransmitted signal impulse has been timed by localmechanism driven by a local speed regulated motor, and every impulseincluding starting and stopping impulses have been governed inelectrical nature by an electrical signal instantly existing in acontrolling circuit.

By positioning each cam 65 in an angular position between its precedingcam 5-! and its following cam 64, there will be attained the effect ofopening the controlled circuit H4 after each and every intelligenceimpulse and therefore between consecutive impulses when such form ofsignal transmission is desired.

A modification of the structure of Fig. 5 is shown in Fig. 7 wherein allcontacts I08 and all levers 95, I03, I02, are omitted and all cams 65are omitted, the cams 64 being transferred to tacts 34 will be closed orwill be permitted to open according to the natureof the receivedintelligence impulse. In each retransmitting operation, the time iscontrolled by local rnotor and cam and the nature of the retransmittedimpulse is controlled by the instant received signal impulses in thecontrolling line circuit.

Throughout the several species and modifications in which the presentinvention has been illustrated for purpose of complete description, thefollowing generic features will be noted. mechanical design for camstarting, cam driving, and cam controlling has been taken in conformityto designs of selectors for receiving printers, and in each species adesign shown suitable for attachment to a receiving printer to form acombined receiver-printer-repeater. In each species the retransmissionis effected by power. driven contacts, the control of the receivedsignal being exercised in the function of determining whether attaininga condition for utilizing contacts of considerable mechanical strength,of firm contact pressure, and of great reliability. Designs are shown inwhich but a single contact tongue is used, thereby achieving greatsimplicity.

Reference is made to application Serial No. 712/51 to Walter J. Zenner,filed February 23, 1934 which discloses one form of a start-stopregenerative repeater,

. What is claimed is:

1. In a telegraphic repeating device, a contact member forretransmitting a received signal, an armature controlled by a receivedsignal, and a timing. cam started into operation under the control ofsaid armature fortlmlng retransmitted signals and cooperating with saidarmature for operating said contact member in accordance with theinstant position of said armature to control the character of theretransmitted signals.

2. In atelegraphic repea device, a contact member for retransmittingreceived signals, an element controlled by successive received signals,a locking member restraining 1 contact member in its set position, and atim 1 cooperating with said element operating said contact memberrepeatedly to ccntroi t .ng of successive retransmitted signalsdetermined by said element.

3. In a telegraphic repeating device for equal length signal intervals,a contact member for retransmitting received signals, an armaturecontrolled by successive received signals, a locking member restrainingsaid contact member, a multiple lobed timing cam, a latch operable bysaid armature to start said timing cam at the beginning of'each signalinterval, and a cam follower for said timing cam releasing said contactmember successively during each cycle of rotation of said cam to controltiming of successive retransmitted signals during each signal interval.

4. In a telegraph device, a single contact member for retransmitting areceived signal, an element controlled by a received signal, a camcontrolled by said element, and means dually controlled by said cam andsaid element and oper- The ating said contact member at a predeterminedinstant to retransmit an instantly received signal.

' 5. In a telegraphic repeating device, a contact member forretransmitting received signals, an armature controlled by successivereceived signals, a start-stop multiple lobed cam, and means duallycontrolled by said cam and by said armature and operating said contactmember repeatedly at predetermined inst-ants to retransmit directly agroup of received signal impulses during a single cycle of said cam. V

6. In a telegraphic repeating device, a contact member forretransmitting received signals, an armature controlled by successivereceived signals, a multiple lobed cam, means dually con trolled by saidcam and by said armature and operating said contact member atpredetermined instants to retransmit a plurality of received signalimpulses during each cycle of said cam, and a latch operable by saidarmature in response to a received timing signal to start said cam.

'7. In a telegraphic repeating device, an armature controlled by areceived signal, a contact member, and cam operated mechanism startedunder control of said armature and cooperating with said armature foroperating said contact member to retransmit said received signal underinstant control of said armature.

8. In a telegraphic repeating device, an armature controlled bysuccessive received signals, a single contact member, cam operatedmechanism started by said armature and adapted to operate said contactmechanism at successive instants of beginning of a plurality of signaltime intervals, and means associated with said armature for controllingsaid cam operated mechanism in accordance with the electrical nature ofan instantly received signal, a

9. In a telegraph repeater, a signal timing device. comprising amultiple lobed timing cam, means for starting said cam upon receipt of areceived timing signal, means for retransmitting signals under controlof said cam at each instant of beginning of time intervals of aplurality of signals, and means controlled by successively receivedsignals at the instant of beginning of retransmission of each receivedsignal and controlling said retransmitting means to' determine theelectrical nature of each retransmitted signal.

10. In a regenerative repeater, a retransmitting contact, a motor drivencam to operate said retransmitting contact to retransmit start and stopsignals invariably at fixed time intervals after receipt of a startingsignal, and means under control of other signals to render sai-d cameffective to operate said retransmitting contact variably at other fixedtime internals and in ac-.

cordance with received signals.

11. In a regenerative repeater, a transmitting contact, a motor drivencam barrel to operate said contact invariably to transmit start and lyby said armature, and a second means to retransmit said code signalscontrolled jointly by the rotary member and the position of saidarmature at the instant of beginning of repeating each signal impulse.

13. In a regenerative repeater, a magnet controlled by received signals,an armature for said magnet, a motor driven rotatable cam controlled tostart into rotation by said magnet, and a retransmitting contact whoseposition in successive intervals of time is determined by said armatureand the time of beginning and end of the irltervals is determined bysaid rotatable cam.

14. In a regenerative repeater, a magnet controlled by received signals,an armature for said magnet, a motor driven rotatable cam controlled tostart into rotation by said magnet, and a retransmitting contact whoseposition in succesretransmitting intervals of time is determined by saidarmature and the length of the retransmitting intervals is determined bysaid rotatable cam.

15. In a telegraph system, means controlled by a received line signal, acontact element adapted to transmit regenerated impulses, a start-stoprotary member, means to lock the contact element in either marking orspacing position, and means to change the contact element from oneposition to the other under the. dual control of said rotary member andsaid first mentioned means Within intervals of control which are smallin comparison with the length of the said regenerated impulses.

15. Telegraphic apparatus including a member having motion in lineal androtary directions, power driven means to move said member, yieldingmeans opposing the motion of said member in rotary direction,selectively operated means controlled by received signals to oppose the.motion of said member in lineal direction to cause it to move in rotarydirection against said yielding means,,and a retransmitting contactoperable by said member.

1'7. Telegraphic apparatus controlled by received signals, including amember having motion in first and second directions, power driven meansto move said member in first direction and operating for each receivedsignal independently of the electrical character of the received signal,yielding means opposing motion of said member in second direction,selectively operated means to oppose motion of said member in firstdirection to cause it to move in second direction against said yieldingmeans, and a signal retransmitting contact operable by said member.

18. In a regenerative telegraphic repeater, a multiple cam, a signalcontrolled member, a se ries of contacts closable under control of saidcam in variable sequence according to control by said signal controlledmember, and invariable means to open the closed contacts ofsaid seriesin sequence.

19. In a telegraph repeater system for retransmitting signals eachcomposed of a start impulse, a rest impulse, and a plurality of variablecode impulses, a start-stop cam, an armature controlled by receivedsignals, a retransmitting contact, and means controlled by said cam andsaid armature jointly to operate said contact to transmit correspondingsignals under the control of said original signals, said armatureexercising control for a small part only of each elementary impulse.

20. In a start-stop telegraph repeating system, start-stop means totransmit telegraph signals each composed of a start impulse, a restimpulse, and a group of code impulses, a retransmitter, means to bringsaid retransmitter under control of said several impulses for a periodin each impulse short in comparison with the duration of an impulse andsubstantially in the middle of each impulse and thereby retransmit aduplication of the original signal lagging substantially one-half of animpulse behind the received impulses, and locking means for saidretransmitter effective between said periods.

21. In a telegraph system adapted for the transmission of signals eachcomposed of an invariable start pulse and a plurality of variable codeimpulses, a cam member, a constantly rotating shaft, means to start saidcam member by coupling said cam member to said shaft for each startimpulse and maintain the coupling while the code impulses are beingreceived, means controlled by the received signals to transmit a new setof signals corresponding electrically to the original signals, and meanscontrolled by the cam member to time every individual impulse formingthe signals. 7

22. In a telegraph system adapted for the transmission of signals eachcomposed of an' invariable start impulse and a plurality of variablecode impulses, a constantly rotating shaft, a rotary member adapted tobe coupled to said rotating shaft, a magnet operated by said signals,means controlled by the magnet to start said cam member by coupling saidmember to said shaft whenever a start impulse is received, cams carriedby said member, a contact, and means controlled by the magnet to causesaid cams to operate said contact to retransmit signals corresponding tothe original signals.

23. Repeater mechanism for regenerating start-stop codes, whichcomprises, a transmit ting cam started directly by a received startingimpulse of a code, means associated with said cam for timing everyimpulse retransmitted including start and stop impulses, and meansincluding a receiving magnet for determining the electrical nature ofevery retransmitted impulse.

24. In a telegraph repeater, a cam having an apex for each impulse of astart-stop code, means for starting said cam in response to a receivedstarting impulse, and means controlled by received impulses andcooperating with each apex of said cam to transmit impulsescorresponding to received impulses.

25. In a telegraph repeater, a cam having an apex for each impulse of astart-stop code,

means for phasing said cam in response to a received timing impulse, andmeans controlled by received impulses and cooperating with each apex ofsaid cam to transmit impulses corresponding to received impulses.

26. In a telegraphic repeating deviceyan electromagnet responsive togroups of signals, each group consisting of synchronizing and selectingsignals, means for controlling the beginning of the synchronizing andselecting signals of each group, mechanism controlled by theelectromagnet in response to a synchronizing signal for rendering saidmeans efiective, a retransmitting contact, and means controlled by theelectromagnet after said means has been rendered effective fordetermining the operation of the retransmitting contact to retransmitsynchronizing and selecting signals. a

27. In a regenerative telegraph repeater, a signal controlled member, aseries of cam projections corresponding to impulses of spacingcharacter, a second series of cam projections corresponding to impulsesof marking character, a retransmitter, and means including a memberengageable by all of said cam projections and engaging saidretransmitter to control the retransmitter from onecam or the otheraccording to the operation of the signal controlled member.

28. In a regenerative start-stop telegraph repeater, a signal controlledmember, a series of parallel connected retransmitting contacts, onecorresponding to the start and stop impulses, one corresponding to eachof the code impulses, means to close and open the start-stop contactunder control of the signal controlled member, means to close the codecontacts under control of the signal controlled member, and means toopen the code contacts independently of the signal controlled member.

29. In a start-stop regenerative repeater, a signal controlled member, asignal transmitting contact, a multiple lobed cam, means to initiate theoperation of the multiple lobed cam under control of the signalcontrolled member, and means to operate the retransmitting contact underthe joint control of the cam and the signal controlled member andeffective to operate the retransmitting contact to retransmit a start,

impulse independent of the position of the signal controlled memberand-to operate the retransmitting contact to transmit code impulseswhose timingseverally is controlled by angular position of said multiplelobed cam and whose electrical characteristics severally are controlledby the position of the signal controlled member.

30. In a telegraphic repeating device, a contact member forretransmitting received signals, an element controlled by the receivedsignals, a timing cam for determining an instant of beginning ofretransmitted code signal impulses normally tending to rotate, meansunder control of said element for releasing said cam for rotation whichcooperates during its rotation with said element for operating saidcontact member to control electrical characteristics in theretransmission of signals as'determined' by said element.

LOUIS M. PO'I'IS.

